they want to see who the person is from the front and if he might be relevant. >> president obama vowed to find those responsible for the bombing. >> any responsible individuals, any responsible groups will feel the full weight of justice. >> reporter: white house officials say they are treating the bombings as an act of terrorism. in boston, susan mcguinness. wjz eyewitness news. >> it's hard to comprehend the frightening moments as not one but two bombs go into the crowd. good morning, ron. >> reporter: what you are about to see is the first video obtained by cbs moments after the attack began. we had an attack. >> oh, my god. oh, my god. oh, my god. oh, my god. >> those are unedited images of the first bombing at the height of the chaos around 2:50 yesterday afternoon. jessica, back to you. >> hard to watch. >>> back here in the wake of the attacks, law enforcement are increasing their presence all over the state. wjz and mike schuh are live downtown with more. good morning, mike. >> good morning, jessica. people are starting to suspect that something could happen. there is no threat